Method of calibration for a video gaming system

ABSTRACT

A method of calibration a video game system can include removing an optical filter that filters out visible light from a field of view of a camera to allow the camera to view visible light. The method can also include displaying a calibration image on a display screen located within the field of view of the camera, processing the video output feed from the camera with a computer processor to identify the calibration image, and calculating with the processor coordinates that represent corners of the display screen in the field of view of the camera once the calibration image is identified.

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

Any and all applications for which a foreign or domestic priority claim is identified in the Application Data Sheet as filed with the present application are hereby incorporated by reference under 37 CFR 1.57 and should be considered a part of this specification.

BACKGROUND Field

The invention is directed to a video gaming system and method of operation, and more particularly to a video gaming system using a light targeting peripheral.

Description of the Related Art

Video games are very popular. Some games involve targeting objects in the game. When playing video games, users provide inputs to the game through a controller or peripheral.

SUMMARY

There is a need for an improved video game system.

In accordance with one aspect, a video game system can include a console, a camera and a light targeting peripheral (LTP), where the LPT can direct non-visible light (e.g., infrared (IR) light) onto a display screen. The camera can be positioned in a location that allows the camera to view the display screen, and the camera can locate the non-visible light dot on the display screen during video game play. The system can be used with any size or type of electronic display (e.g., any type of television, computer screen, etc.), any type of non-electronic display (e.g., projector screen, a wall surface) on which the video game is projected, or a display area that does not display a video game image (e.g., a poster used for calibration), where video game images are provided by a separate device (e.g., a virtual reality device, such as a head mounted display worn by the user), for example.

In accordance with another aspect, a video game system is provided. The system comprises a console configured to transmit one or more visual or aural effects of a video game to a display screen. The system also comprises a camera positionable so that it can view the display screen, the camera configured to communicate with the console. The system also comprises a light targeting peripheral comprising a trigger and a non-visible light source, the light targeting peripheral configured to direct a non-visible light onto the display screen and to communicate with one or both of the console and the camera when the trigger is actuated, the camera configured to locate a position on the display screen targeted by the light targeting peripheral upon the actuation of the trigger irrespective of a size and type of the display screen and to communicate said position to the console.

In accordance with another aspect, a video game system is provided. The system comprises a console configured to transmit one or more visual or aural effects of a video game and a camera positionable so that it can view a display, the camera configured to communicate with the console. The system also comprises a light targeting peripheral comprising a trigger and a non-visible light source, the light targeting peripheral configured to direct a non-visible light onto the display and to communicate with one or both of the console and the camera when the trigger is actuated, the camera configured to locate a position on the display targeted by the light targeting peripheral upon the actuation of the trigger irrespective of a size and type of the display screen and to communicate said position to the console.

In accordance with another aspect, a video game system is provided. The system comprises a camera positionable so that it can view a display. The camera comprises an optical filter operable to filter out visible light while allowing non-visible light to pass through a lens of the camera during operation of a video game. The system also comprises a light targeting peripheral comprising a trigger and a non-visible light source, the light targeting peripheral configured to direct a non-visible light onto the display and to communicate with the camera when the trigger is actuated, the camera configured to locate a position on the display targeted by the light targeting peripheral upon the actuation of the trigger irrespective of a size and type of the display.

In accordance with another aspect, a method of calibrating a video game system is provided. The method comprises removing an optical filter that filters out visible light from a field of view of a camera to allow the camera to view visible light, displaying a calibration image on a display screen located within the field of view of the camera, processing the video output feed from the camera with a computer processor to identify the calibration image, and calculating with the processor coordinates that represent corners of the display screen in the field of view of the camera once the calibration image is identified.

In accordance with another aspect, a method of calibrating a video game system is provided. The method comprises removing an optical filter that filters out visible light from a field of view of a camera to allow the camera to view visible light, flashing a calibration image on and off on a display screen located within the field of view of the camera, processing the video output feed from the camera with a computer processor to identify the calibration image, and calculating with the processor coordinates that represent corners of the display screen in the field of view of the camera once the calibration image is identified.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic drawing of one embodiment of a video gaming system.

FIG. 2A shows one embodiment of a camera for the system in FIG. 1, with an optical filter positioned in front of the lens to filter out visible light and allow non-visible light to pass into the camera lens.

FIG. 2B shows the camera of FIG. 2A, with an optical filter positioned out of the way to allow visible light into the camera lens.

FIG. 2C shows a schematic view of the electronics of the camera of FIG. 1.

FIG. 3 shows a flowchart for one method of calibrating the camera.

FIG. 3A shows one embodiment of a calibration image.

FIG. 3B shows a calibration step in the method of FIG. 3.

FIG. 3C shows a calibration step in the method of FIG. 3.

FIG. 3D shows another embodiment of a calibration step in the method of FIG. 3.

FIG. 3E shows another embodiment of a calibration step in the method of FIG. 3.

FIG. 4 shows a flowchart for one method of recalibrating the camera.

FIG. 5 shows a flowchart of one embodiment of a tracking method for the video gaming system.

FIG. 5A shows a schematic drawing of the video gaming system in use.

FIG. 5B shows a step in the tracking method of FIG. 5.

FIG. 5C shows another embodiment of a step in the tracking method of FIG. 5.

FIG. 5D shows another embodiment of a step in the tracking method of FIG. 5.

FIG. 5E shows a step in the tracking method of FIG. 5.

FIG. 5F shows a step in the tracking method of FIG. 5.

FIG. 6 is a schematic block diagram of the electronics of a light targeting peripheral used with the video gaming system of FIG. 1.

FIG. 7 is a schematic drawing of the video gaming system in use by two individuals during use.

DETAILED DESCRIPTION

FIG. 1 shows one embodiment of a video gaming system 100. The system 100 can include a console 10, a light locating camera 20 that utilizes an optical filter 30, and a light targeting peripheral (LTP) 40 (e.g., a light gun). Advantageously, the system 100 can be used with any size or type of display screen, including any type of television (e.g., LCD, LED, CRT, Plasma, etc.), computer monitor, display area (e.g., a projector screen, a wall area) that can display a video game image (e.g., projected onto the display area by a projector), or a display area that does not display a video game image (e.g., a poster used for calibration), where video game images are provided by a separate device (e.g., a virtual reality device, such as a head mounted display worn by the user), for example.

The LTP 40 can direct non-visible light (e.g., an infrared (IR) light, ultraviolet (UV) light, etc.) onto a display screen 50, and the location of the light on the display screen 50 can be located by the camera 20, as discussed in more detail below. The console 10 can communicate with the display screen 50 (e.g., via a cable 12), and the camera 20 can communicate with the console 10 (e.g., via a cable 14). The console 10 can operate the video game and communicate with the display screen 50 to display images from the video game and provide audio effects associated with the video game. In some embodiments, one or more of the console 10, camera 20 and LTP 40 can communicate wirelessly (e.g., via an RF link).

In the illustrated embodiment, the LTP 40 can communicate wirelessly with the camera 20, such as via an RF link. In another embodiment, the LTP 40 can additionally, or alternatively, communicates with the console 10. For example, if the image processing is at least partially performed by software in the console 10, the LTP 40 can communicate with the console 10. The LTP 40 can have a wireless transmitter 42 to transmit data to one or both of the console 10 and the camera 20, which can have a wireless receiver 22, as discussed further below. Optionally, the LTP 40 can also have a wireless receiver to receive data from one or both of the console 10 and the camera 20. In still another embodiment, the LTP 40 can communicate with one or both of the camera 20 and console 10 via a cable. The LTP 40 can have a light source 44, which in one embodiment can be an infrared laser, where the IR laser can have optics to collimate and focus the laser so that the laser is straight, and where the size of the IR light dot from the laser has the same size regardless of the distance of the LTP 40 from the display screen 50. In another embodiment, the LTP 40 can have an infrared LED as the light source 44, with optics to focus the IR light from the LED. The size of the IR light dot will vary with the distance of the LTP 40 is from the display screen 50 (e.g., the IR light dot will be larger the farther the LTP 40 is from the display screen 50). However, in other embodiments, the light source 44 of the LTP 40 can use other forms of non-visible light (e.g., ultraviolet light).

The LTP 40 can optionally be customizable. In one embodiment, the LTP 40 can be a passive device and include a non-visible light emitter (e.g., an IR light emitter) as the light source 44 and a trigger 46. In one embodiment, actuation of the trigger 46 can break or switch off the non-visible light that is otherwise continuously emitted. In another embodiment, actuation of the trigger 46 does not break or switch off the non-visible light but communicates with the camera 20 and/or console 10 when the trigger 46 is actuated. In still another embodiment, the actuation of the trigger 46 can turn on the non-visible light momentarily, where the non-visible light is otherwise switched off, as described further below. If the LTP 40 is a wireless device, it can also include one or more batteries (not shown) and the wireless transmitter 42. Where the LTP 40 is a passive device, it does not receive any data from the camera 20.

In another embodiment, the LTP 40 can be an active device. In this embodiment, in addition to having the features described above for a passive device, the LTP 40 can include a receiver (e.g. wireless receiver) and circuitry (e.g., integrated circuit or IC) that allows it to have additional functionality. For example, the LTP 40 can receive data from the camera 20 that allows it to control aspects of the video game itself

In another embodiment, the LTP 40 can include additional control inputs in addition to the trigger 46 that allow the LTP 40 to provide additional inputs to the video game, such as when the LTP 40 is an active device as described above. For example, the LTP 40 can include one or more of a D-pad, one or more input buttons, and an analog joystick.

In another embodiment, the LTP 40 can have one or more sensors, such as accelerometers, magnetometers, gyroscopes, that can be used in inertial tracking of the LTP 40 by tracking software of the system 100. Said inertial tracking can facilitate the determination of the location of the non-visible light dot when the trigger is actuated (e.g., where the non-visible light is continually emitted and therefore continually tracked by the tracking software) by providing the tracking software with additional information about the direction of movement and/or orientation of the LTP 40 before the trigger 46 was actuated.

In another embodiment, the LTP 40 can have one or more expansion ports that can receive a controller to provide additional control in the video game. In such an embodiment, the LTP 40 can operate in tandem with the controller to provide a user with the ability to control more aspects of the video game than if the controller was not coupled to the LTP 40.

The camera 20 can be positioned in any location that allows it to view or “look” at the display screen 50 (e.g., at a location below, above, to the left of, to the right of, close to, or far from the display screen 50). Moreover, the camera 20 can be supported on any suitable surface, such as the floor, on a table, a counter, etc. The camera 20 can be mounted in any suitable manner. In one embodiment, the camera 20 can have a clamp that allows it to mount, for example, to a table (e.g., coffee table) or chair. In another embodiment, the camera 20 can have vacuum mount system (e.g., one or more vacuum cups or suction cups) that can removably mount the camera 20 to a support surface (such as a table surface, floor, etc.) to generally fix the location of the camera 20. In still another embodiment, the camera 20 can have one or more pads (friction pads) on a bottom surface of the camera 20 to generally fix the location of the camera 20. In one embodiment, the camera 20 can have a low profile that inhibits unintended movement of the camera 20, for example, when bumped by a user. Optionally, the camera 20 can be dome shaped. In one embodiment, the camera 20 can have an accelerometer or other type of orientation sensor (e.g., magnetometer) that can provide information on the orientation of the camera 20, which can be used by the software (e.g., calibration software or tracking software, as described further below) to ensure that the location of a non-visible light when the trigger 46 is actuated is correctly translated onto the display screen 50.

With continued reference to FIG. 1, the camera 20 can have an optical filter 30 that filters out visible light but allows the camera 20 to view non-visible light, such as a low-pass IR optical filter, where the filter 30 is selectively applied to filter out visible light. In one embodiment, the optical filter 30 can resemble a piece of black plastic. FIG. 2A shows an embodiment of the camera 20 with the optical filter 30 positioned in front of the lens 23 of the camera 20 to filter out visible light while allowing non-visible light (e.g., IR light) to pass through the lens 23 of the camera 20. FIG. 2B shows the camera 20 of FIG. 2A, where the optical filter 30 is positioned out of the way of the lens 23 to allow visible light to pass through the lens 23 of the camera 20.

In one embodiment, the filter 30 is a switchable or removable filter 30 that can be selectively positioned in front of the lens 23 of the camera 20. For example, in one embodiment, the optical filter 30 can be positioned mechanically in front of the lens 23 of the camera 20 and moved out of the way from in front of the lens 23 of the camera 20, such as with a stepper motor. However, other suitable mechanisms can be used to position the optical filter 30 in front of the lens 23 of the camera 20 as well as move it out of the way of the lens 23 of the camera 20, such as a sliding mechanism. In still another embodiment, the optical filter 30 can be manually positioned in front of the lens 23 of the camera 20 (e.g., by a user) as well as removed from in front of the lens 23. In another embodiment, the camera 20 can have an electronically switchable optical filter (e.g., night mode), as opposed to a physical optical filter, that can be selectively operated to filter out visible light while allowing non-visible light (e.g., IR light) to pass through the lens 23 of the camera 20. In some embodiments, the camera 20 can be a wide bandwidth camera, where the IR blocking filter has been removed so that the camera 20 can view IR through visible light. In one embodiment, the camera 20 is a Raspberry Pi Noir IR camera.

FIG. 2C shows one embodiment of an electronics diagram for the camera 20. The camera 20 can include an optical filter 30 and an actuator 32 that selectively positions the filter 30 in front of the lens 23 to filter out visible light. Optionally, the light that passes through the lens 23 can be processed by an image processing circuit 24 in the camera 20. In another embodiment, the camera 20 can exclude the image processing circuit and such circuit can be in the console 10. The camera 20 can also include a communication module, which can be connected to the wireless receiver 22 and the cable 14 that connects the camera 20 to the console 10. The camera 20 can also have control circuitry 27 for controlling the operation of the camera 20, which can optionally include one or more sensors (e.g., accelerometer, magnetometer) and a memory 28. In one embodiment, the camera 20 received power from an outside source via a power module 29 and cable. In another embodiment, the camera 20 can be powered by one or more batteries (not shown).

Calibration

Prior to use of the system 100, the position of the camera 20 is calibrated relative to the display screen 50. FIG. 3 shows a flowchart of a calibration method 200 for the camera 20. The optical filter 30 is removed 210 from the camera 20 (or the optical filter is switched off where the camera 20 has an electronically switchable optical filter) so that the camera 20 can see visible light. A calibration image is displayed 230 on the display screen 50 (e.g., by the console 10). Image recognition software processes 250 the visible light video feed (e.g., continually reads the video output) from the camera 20 to find the calibration image. In one embodiment the image processing is at least partially performed by the camera 20 (via the image processing circuit 24, as described above). In another embodiment, the image processing is at least partially performed by the console 10. Once the calibration image is found by the software, the software calculates 270 camera coordinates that represent the corners of the display screen 50 in the field of view of the camera 20, at which point the calibration of the camera 20 is completed. In some embodiments, where the camera 20 has an extra wide angle lens that distorts the image and where the display screen 50 appears curved, the image recognition software utilizes additional algorithms to undistort the image.

With respect to step 230, various different images can be used in the calibration method 200. In one embodiment, the calibration image can be a QR code. In another embodiment, the calibration image can be a plain screen image that cycles through a known sequence of colors on the display screen 50 (e.g., all red, all blue, all green, etc.), where the image recognition software can process the image and look for pixels in the live feed from the camera 20 that mimics the sequence of the calibration image.

FIG. 3A shows one embodiment of a calibration image 230A that can be used in step 230 of the calibration method 200, where the calibration image 230A includes nine markers 232 that are displayed on the display screen 50. The image recognition software can process 250 the calibration image using a Harris Corner Detection algorithm. In another embodiment, the image recognition software can process 250 the calibration image using other suitable algorithms, such as a Features from Accelerated Segment Test (FAST) algorithm. Further details on the FAST algorithm can be found in the following articles, all of which are incorporated by reference: Edward Rosten et al., Fusing Points and Lines for High Performance Tracking, IEEE International Conference on Computer Vision, October 2005; Edward Rosten et al., Machine Learning for High-speed Corner Detection, European Conference on Computer Vision, May 2006; and Edward Rosten et al., FASTER and Better: A Machine Learning Approach to Corner Detection, IEEE Trans. Pattern Analysis and Machine Intelligence, 2010.

The Harris Corner Detection algorithm returns a numerical value for each pixel in the camera image representative of a likelihood of the pixel being in a corner in the image. The algorithm filters out any pixel below a threshold value and generates a list of points (x, y coordinates) within the camera image that represent potential corners. The list of points are processed and grouped into clusters. For example, each point is processed to determine if it is within a distance threshold from any other point previously processed within an existing cluster; if the point is within the threshold it is added to the cluster. If said point is not within the threshold from another point, a new cluster is started with said point. This process is repeated until all points are processed. The center of each cluster is then calculated, which can be defined as the average coordinate of all the points in the cluster, and the radius of each cluster is also calculated, which is the furthest distance any of the points in the cluster is from the center of the cluster. Clusters having less than a predetermined number of points (e.g., less than 2 points) are rejected or filtered out.

FIG. 3B shows a sub-step 230B of the processing step 250 of the calibration process 200 with the calibration image on the display screen 50, where all the detected clusters are represented by a circle and an identification number. As shown in FIG. 3B, the software has detected most of the reference marks, but there may be a few that are misidentified (e.g., no. 7 in FIG. 3B).

FIG. 3C shows a sub-step 230C of the processing step 250 in the calibration process 200 with the calibration image on the display screen 50. The image recognition software determines if the clusters represent a screen by using the known relationship of the reference marks in the calibration image to each other. Each cluster in the list of clusters is evaluated as an “assumed” center point of the display screen 50 by determining if it meets the following set of rules. The image recognition software looks for pairs of clusters that can be connected by a line 234 that passes in close proximity to the center point of the “assumed” center point, and where the end points of such a line are approximately at the center of another line defined by another pair of clusters. In FIG. 3C, the line from cluster 1 to cluster 7 passes through the “assumed” center point (at cluster 4) and the ends of said line are approximately at the center of the lines that connect clusters 0 to 2 and clusters 6 to 8. Similarly, the line 234 that passes from cluster 3 to 5 passes through the “assumed” center point (at cluster 4) and the ends of said line are approximately at the center of the lines that connect clusters 2 to 8 and that connect clusters 0 to 6. The end point lines are evaluated to ensure they form a closed rectangle around the center point, and diagonal lines from the intersection of the four end point lines are evaluated to confirm the lines pass through the “assumed” center point. Additionally, angles between the four lines (e.g., between the line from cluster 0 to 2, and line from cluster 2 to 8) are evaluated to determine if the angle meets a threshold value (e.g. around 75 degrees). Because the camera 20 may be askew to the display screen 50, the angle between the lines may not be approximately 90 degrees. Once the image recognition software has confirmed the “assumed” center point of the display screen 50 is the center point of the display screen 50, the software determines 270 the coordinates of the four corners of the display screen 50 within the field of view of the camera 20 and the calibration is complete (e.g., P1-P4 in FIG. 5B).

In another embodiment of the calibration method 200, the calibration image, such as the calibration image 230A in FIG. 3A, can be flashed on in one frame on the display screen 50 (e.g., by the console 10) and turned off in the next frame on the display screen 50. For example, in one embodiment the calibration image 230A can be flashed on for 100 ms and turned off for 100 ms. However, in other embodiments, the time the calibration image 230A is on and off can vary (e.g., can be about 150 ms). In the illustrated embodiment, the calibration image 230A has nine markers. However, in other embodiments the calibration image 230A can have a different number of markers (e.g., fewer markers, more markers). In one embodiment, the calibration image 230A can have only four markers at the corners.

Image recognition software can process 250 the feed from the camera 20 frame by frame and perform frame subtraction to identify the changes in what is shown in the display screen 50 (e.g., identify changes on the display screen when the calibration image 230A is turned on and off). In one embodiment, the camera 20 can operate at about 90 frames per second; however, in other embodiments, the camera 20 can operate at a larger or smaller number of frames per second. Where the flashed frames of the calibration image 23A are not synchronized with the camera frames, the image processing software can use an algorithm, including an accumulator or counter, to account for the calibration image flashing at a slower rate than the camera operation, in order to perform the frame subtraction step and identify the calibration image. In one embodiment, the software compares a camera frame with a previous frame (e.g., a frame from 10-15 previous frames) that is not the immediately previous frame. In another embodiment, the software compares a camera frame with the immediately previous frame.

Due to the flashing of the calibration image 230A on the display screen 50, the frame subtraction process results in the background detail being removed (e.g., background detail that may be interpreted as false corners) and leaving only the calibration markers in a black screen (not shown), as shown in FIG. 3D. In some embodiments, the image calibration software can look for the flashing calibration image over a number of frames to identify the markers in the calibration image as reliable markers. The image recognition software can then associate the markers with the corners of the screen and the software determines 270 the coordinates of the four corners on the display screen 50 within the field of view of the camera 20 (e.g., connects the markers with lines to define the corners of the display screen 50 within the field of view of the camera 20), as shown in FIG. 3E. The flashing of the calibration image and use of frame subtraction can advantageously simplify and speed-up the calibration process.

In one embodiment, the calibration method 200 can be performed every time the system 100 is turned on, prior to the user playing a game. In another embodiment, the calibration method 200 can be performed at a predetermined time (e.g., once a day, once every other day, once every week, etc.).

Recalibration

FIG. 4 shows one embodiment of a recalibration method 300, which can be performed after the calibration method 200 has been completed (e.g., while in play mode, discussed further below). If the camera 20 position moves (e.g., as a result of a player bumping into the camera), the camera 20 can be recalibrated relative to the display screen 50. With continued reference to FIG. 4, if motion of the camera 20 is sensed 310 (e.g., with one or more sensors in the camera 20, such as an accelerometer), the software determines 320 if the sensed motion is above a predetermined threshold (e.g., above a predetermined force magnitude). In one embodiment, the one or more sensors in the camera 20 that sense whether the camera 20 has been moved can be the same sensors used to determine the orientation of the camera 20, as discussed above; in another embodiment, the sensors that sense movement of the camera 20 to determine if recalibration should be performed can be separate from the one or more sensors that sense the orientation of the camera 20. If the sensed movement is above the threshold, then the calibration method 200 is performed again (see FIG. 3). In one embodiment, if the sensed motion is above the predetermined threshold, the system 100 may automatically being the recalibration of the camera 20. In another embodiment, the system 100 can provide feedback to the user (e.g., visual and/or audio feedback) that the camera 20 needs to be recalibrated, at which point the video game is paused and the camera 20 is recalibrated. If the sensed motion 310 is not above the threshold, the software determines that recalibration is not needed.

Play Mode-Tracking Non-Visible Light

FIG. 5 shows a flowchart of a method of tracking the non-visible light (e.g., IR light) from the LTP 40 when the system 100 is in play mode (shown in FIG. 5A). Once calibration of the camera 20 is completed, the optical filter (such as optical filter 30) is positioned 410 in front of the lens 23 of the camera 20 to filter out visible light while allowing non-visible light to pass through the lens 23 of the camera 20.

The tracking software searches the feed from the camera 20 for non-visible light (e.g., IR light). As shown in FIG. 5B, there may be multiple sources of non-visible light, such as background IR light on a wall IR2, IR light on an LED TV IR3, IR reflection on the display screen 50 IR4, so the software determines 430 which source is most likely to be the non-visible light IR1 from the LTP 40. In one embodiment, the software determines which source in the video feed is the non-visible light IR1 from the LTP 40 by filtering out intensity values below a predetermined threshold value (e.g., to filter out background light). In another embodiment, the software additionally, or alternatively, ignores (filters out) light sources that aren't round (or less dense, as discussed further below). For example, the software searches for a group of pixels that form a dot (e.g., generally circular shape) with the highest concentration or density of pixels, while considering the intensity values. In still another embodiment, the software ignores (filters out) light sources that are outside the quadrangle defined by the corners of the display screen (P1-P4 in FIG. 5B) that are in the field of view of the camera 20. However, other suitable techniques for identifying the non-visible light IR1 from the LTP 40 can be used.

In another embodiment, the image processing software compares a frame (see FIG. 5C), in which the non-visible light IR1 from the LTP 40 has not been actuated, with the camera frame in FIG. 5B, in which the non-visible light IR1 from the LTP 40 has been actuated, and uses a frame subtraction algorithm, as discussed above, to filter out sources of non-visible light that are not associated with the LTP 40, resulting in the image on FIG. 5D,where non-visible light from other than the LTP 40 has been filtered out. In some embodiments, the image processing software can further use an algorithm to confirm that the remaining non-visible light on the screen 50 corresponds to the light from the LTP 40. For example, as discussed above, the software can search for a group of pixels that form a dot (e.g., generally circular shape) with the highest concentration or density of pixels, while considering the intensity values.

Once the location of the non-visible light IR1 from the LTP 40 is detected (e.g., at location t_(x), t_(y) in FIG. 5B or FIG. 5D), the tracking software expresses 450 the position of the non-visible light dot IR1 as a proportion of the quadrangle (P1-P4). In one embodiment, shown in FIG. 5E, this is done by projecting a line from one of the corners (e.g., P1) of the quadrangle through the detected location (t_(x), t_(y)) of the non-visible light dot IR1 (e.g., IR light dot), calculating where it intersects the opposite side of the quadrangle (P1-P4), and expressing said intersection on the opposite side of the quadrangle (P1-P4) as a proportion of the distance L2 along said opposite side (e.g., Y1/Y2); this process of projecting a line from a corner through the detected location of the non-visible light dot and calculating the intersection of the line on an opposite side of the quadrangle and expressing it as a proportional distance along said opposite side can be repeated for one or more other corners of the quadrangle (P1-P4).

As shown in FIG. 5F, the tracking software then maps 470 said proportional distances (e.g., L2*Y1/Y2, L1*X1/X2 in FIG. 5E) on the sides of the quadrangle (P1-P4) onto the display screen 50 to identify intersection points along corresponding borders of the display screen 50 (e.g., X1/X2 and Y1/Y2 in FIG. 5E is equal to X3/X4 and Y3/Y4 in FIG. 5F, respectively). Lines are then calculated 490 from said intersection points to one or more corners (e.g., P1, P3) of the display screen 50 opposite the intersection location, and the intersection point of all the lines corresponds to the location (t_(rx), t_(ry)) of the non-visible light dot (e.g., IR light dot) on the display screen 50.

In the tracking process described above, only two lines need to be drawn from corners of the quadrangle (P1-P4) through the detected location (t_(x), t_(y)) of the non-visible light dot and onto opposite sides of the quadrangle, which can then be translated to the display screen 50 as discussed above to translate the camera view to the display screen 50 or “game space”. However, use of four lines (one from each of the corners of the quadrangle) that intersect the detected non-visible light dot location can improve the accuracy of providing the non-visible light dot location on the display screen 50 and provides for error redundancy.

In one embodiment, the non-visible light (e.g., IR light) is continually projected by the LTP 40, and the software is constantly tracking the non-visible light dot, but can in one embodiment only record its position once the trigger 46 on the LTP 40 is actuated. In another embodiment, the non-visible light is continually projected by the LTP 40, but the light is switched off when the trigger 46 is actuated; in this embodiment, the tracking software searches the feed from the camera 20 for the location where the non-visible light dot is missing, and translates this location to the display screen 50, as discussed above. Advantageously, this method of continually projecting the non-visible light and recording only when the trigger 46 is actuated provides a relatively fast system response (e.g., minimum latency) from the actuation of the trigger 46 to the video game providing feedback to the user (e.g., visual and/or audio feedback). However, the location of the non-visible light dot that is recorded corresponds to a location where the LTP 40 was pointed a fraction of a second prior, and one or more batteries of the LTP 40 may drain more quickly (e.g., where the LTP 40 is wireless) since the non-visible light would be constantly projected.

In another embodiment, the non-visible light is only projected by the LTP 40 when the trigger 46 is actuated. The software then searches the feed from the camera 20 to identify the non-visible light dot, as discussed above. Advantageously, this method results in increased accuracy of the actual position when the trigger 46 is actuated, and the one or more batteries of the LTP 40 (e.g., where the LTP 40 is wireless) may drain more slowly since the light is only projected when the trigger 46 is actuated. However, due to the latency in reviewing the feed from the camera 20, it may take several milliseconds for the non-visible light dot to be identified in the camera feed and communicated to the console 10, which may increase the latency for the user to receive feedback (e.g., visual and/or audio feedback) following the actuation of the trigger 46.

FIG. 6 shows a schematic diagram of the electronics in the LTP 40. The LTP 40 can have a light source or emitter 44, as discussed above, which can be electrically connected to control circuitry 41. The control circuitry 41 can be electrically connected to a communication module 43, which includes a wireless transmitter 42, as discussed above. The LTP 40 can also have a switch 47 that is actuated by the trigger 46 and that communicates with the control circuitry 41 to indicate when the trigger 46 has been actuated. The LTP 40 can also have one or more batteries 48 that can power the electronics, including the control circuitry 41, communication module 43 and switch 47. In one embodiment, as discussed above, the LTP 40 can have one or more sensors, which can be part of the control circuitry 41.

Though FIG. 1 shows a single LTP 40, one of skill in the art will recognize that more than one LTP 40 can be utilized while playing the video game (e.g., two LTPs 40, four LTPs 40), depending on the number of players, as shown in FIG. 7. As discussed above, the LTP 40 can communicate with one or both of the camera 20 and console 10 via an RF link. To accommodate multiple users during a video game, the system 100 can utilize a time division multiplexing method so that the multiple LTPs 40 are not all allowed to be actuated at the same time.

The console 10 can optionally have one or more processors, a communication interface, a main memory, a ROM and a storage device, which can be connected to a bus.

While certain embodiments of the inventions have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the disclosure. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms. Furthermore, various omissions, substitutions and changes in the systems and methods described herein may be made without departing from the spirit of the disclosure. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the disclosure. Accordingly, the scope of the present inventions is defined only by reference to the appended claims.

Features, materials, characteristics, or groups described in conjunction with a particular aspect, embodiment, or example are to be understood to be applicable to any other aspect, embodiment or example described in this section or elsewhere in this specification unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. The protection is not restricted to the details of any foregoing embodiments. The protection extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Furthermore, certain features that are described in this disclosure in the context of separate implementations can also be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation can also be implemented in multiple implementations separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations, one or more features from a claimed combination can, in some cases, be excised from the combination, and the combination may be claimed as a subcombination or variation of a sub combination.

Moreover, while operations may be depicted in the drawings or described in the specification in a particular order, such operations need not be performed in the particular order shown or in sequential order, or that all operations be performed, to achieve desirable results. Other operations that are not depicted or described can be incorporated in the example methods and processes. For example, one or more additional operations can be performed before, after, simultaneously, or between any of the described operations. Further, the operations may be rearranged or reordered in other implementations. Those skilled in the art will appreciate that in some embodiments, the actual steps taken in the processes illustrated and/or disclosed may differ from those shown in the figures. Depending on the embodiment, certain of the steps described above may be removed, others may be added. Furthermore, the features and attributes of the specific embodiments disclosed above may be combined in different ways to form additional embodiments, all of which fall within the scope of the present disclosure. Also, the separation of various system components in the implementations described above should not be understood as requiring such separation in all implementations, and it should be understood that the described components and systems can generally be integrated together in a single product or packaged into multiple products.

For purposes of this disclosure, certain aspects, advantages, and novel features are described herein. Not necessarily all such advantages may be achieved in accordance with any particular embodiment. Thus, for example, those skilled in the art will recognize that the disclosure may be embodied or carried out in a manner that achieves one advantage or a group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.

Conditional language, such as “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements, and/or steps. Thus, such conditional language is not generally intended to imply that features, elements, and/or steps are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without user input or prompting, whether these features, elements, and/or steps are included or are to be performed in any particular embodiment.

Conjunctive language such as the phrase “at least one of X, Y, and Z,” unless specifically stated otherwise, is otherwise understood with the context as used in general to convey that an item, term, etc. may be either X, Y, or Z. Thus, such conjunctive language is not generally intended to imply that certain embodiments require the presence of at least one of X, at least one of Y, and at least one of Z.

Language of degree used herein, such as the terms “approximately,” “about,” “generally,” and “substantially” as used herein represent a value, amount, or characteristic close to the stated value, amount, or characteristic that still performs a desired function or achieves a desired result. For example, the terms “approximately”, “about”, “generally,” and “substantially” may refer to an amount that is within less than 10% of, within less than 5% of, within less than 1% of, within less than 0.1% of, and within less than 0.01% of the stated amount. As another example, in certain embodiments, the terms “generally parallel” and “substantially parallel” refer to a value, amount, or characteristic that departs from exactly parallel by less than or equal to 15 degrees, 10 degrees, 5 degrees, 3 degrees, 1 degree, or 0.1 degree.

The scope of the present disclosure is not intended to be limited by the specific disclosures of preferred embodiments in this section or elsewhere in this specification, and may be defined by claims as presented in this section or elsewhere in this specification or as presented in the future. The language of the claims is to be interpreted broadly based on the language employed in the claims and not limited to the examples described in the present specification or during the prosecution of the application, which examples are to be construed as non-exclusive. 

What is claimed is:
 1. A method of calibrating a video game system, comprising: removing an optical filter that filters out visible light from a field of view of a camera to allow the camera to view visible light; displaying a calibration image on a display screen located within the field of view of the camera; processing the video output feed from the camera with a computer processor to identify the calibration image; and calculating with the processor coordinates that represent corners of the display screen in the field of view of the camera once the calibration image is identified.
 2. The method of claim 1, wherein removing the optical filter includes mechanically moving the optical filter out of the field of view of the camera.
 3. The method of claim 1, wherein removing the optical filter includes turning off an electronically switchable optical filter.
 4. The method of claim 1, wherein processing the video feed from the camera includes continuously processing the video output feed.
 5. The method of claim 1, wherein said processing is performed at least in part by the camera.
 6. The method of claim 1, wherein said processing is performed at least in part by a console of the video game system.
 7. The method of claim 1, wherein displaying the calibration image includes displaying an image with multiple markers and wherein processing includes identifying said markers.
 8. The method of claim 1, wherein displaying the calibration image includes cycling a known sequence of colors on the display screen and processing includes identifying pixels in the video output feed that correspond to the sequence of the calibration image.
 9. The method of claim 1, further comprising sensing a motion of the camera prior to removing the optical filter.
 10. The method of claim 9, wherein sensing the motion of the camera includes sensing with one or more sensors that the motion of the camera is above a threshold.
 11. The method of claim 10, further comprising notifying a user of the video game system when sensed motion is above the threshold.
 12. The method of claim 10, wherein the removing, displaying, processing and calculating steps automatically occur when the sensed motion of the camera is above the threshold.
 13. A method of calibrating a video game system, comprising: removing an optical filter that filters out visible light from a field of view of a camera to allow the camera to view visible light; flashing a calibration image on and off on a display screen located within the field of view of the camera; processing the video output feed from the camera with a computer processor to identify the calibration image; and calculating with the processor coordinates that represent corners of the display screen in the field of view of the camera once the calibration image is identified.
 14. The method of claim 13, wherein removing the optical filter includes mechanically moving the optical filter out of the field of view of the camera.
 15. The method of claim 13, wherein removing the optical filter includes turning off an electronically switchable optical filter.
 16. The method of claim 13, wherein flashing the calibration image on and off includes flashing on the calibration image in one frame on the display screen and turning off the calibration image in the next frame on the display screen.
 17. The method of claim 13, wherein processing the video feed from the camera includes performing frame subtraction to identify changes in the video output feed when the calibration image is turned on and off and thereby identify the calibration image.
 18. The method of claim 13, wherein displaying the calibration image includes displaying an image with multiple markers and wherein processing includes identifying said markers.
 19. The method of claim 13, further comprising sensing a motion of the camera above a threshold prior to removing the optical filter.
 20. The method of claim 19, wherein the removing, flashing, processing and calculating steps automatically occur when the sensed motion of the camera is above the threshold. 